Spawn's Hellblasts were shown to be powerful enough to melt down the Gates of Heaven, they were powerful enough to knock out Savage Dragon, they were powerful enough to kill Redeemer, who was specifically made by God to kill Spawn (was called Anti-Spawn at the time), were powerful enough to keep an Ancient God (much much MUCH above Skyfather) at bay (stalemated).
Spawn's got complete control over the nature around him. Not saying this would be a decisive factor, but maybe it could slow Lobo down with all the Earthquakes and tidal waves he'd be facing.
Spawn's regeneration is like i said one of the best i've seen in comics. He was ripped in half and was back in one piece the next page, he ripped his heart out and it regrew in two panels, he was cut up into several pieces (both legs chopped off, an arm, and his head i think) and he was ok in a few minutes.
Spawn's magic abilities include transmutation of matter into anything he pleases. Whether it's a car or a box of wine, or a sword, or etc. etc., he can do it.
Spawn's suit gives him a warning before attacks when he is unaware, so he's not going to get surprised.
Spawn's chains have been shown to be powerful enough to restrain an Ancient God, they can grow to any length and they can be used to transform into constructs like GLs do.
Spawn has shown the power to alter reality, as well as banish people to other dimensions.
Raenis the hellspawn killed the entire Olympian pantheon and became ruler of the Universe.